The McCormick tins appear to be the same size, but the tin on the left contains 8 ounces of ground black pepper and the one in the middle has 6 ounces. The smaller Watkins tin also contains 6 ounces of pepper.

So Watkins is arguing that McCormick was deceiving customers by reducing the amount of pepper in its non-transparent containers while not reducing the size of the tins.

Watkins claims the move hurt sales of its spices, which are often displayed right next to McCormick’s products.

As the Minneapolis Star Tribune has reported, McCormick says there was no false advertising because the correct product weight amount was always listed on the front label.

McCormick also faces a class-action lawsuit from consumers over the matter.

Bottom line: While this case makes its way through the federal court system, it’s a good reminder for shoppers to compare the product weight of similar items, not simply the price alone.